Ducting expansion joints are usually flexible connectors which are designed to provide stress relief in ducting systems to absorb movement in the component parts of the ducting caused by thermal changes. Such ducting expansion joints also act as vibration isolators and compensate for minor misalignment of interconnecting ducts. Such expansion joint structures are also fabricated from a variety of metallic or non-metallic materials including synthetic elastomers, fabrics, insulation materials, and plastics, depending on the designs. Such ducting expansion joints also find many applications, such as in smelters, refuse incineration and power generation plants, such as coal-or oil-fired plants, gas turbine plants, coal/oil/gas cogeneration plants, nuclear power plants, and also in pulp and paper plants and refineries, foundries, steel mills, etc.